Question

the passage below describes an experiment. joys manager at the pet store asked her to determine how to best keep algae off the walls of the fish tanks. joy prepared six 20 - gallon fish tanks, each with three goldfish. she added 10 snails to two of the tanks, 20 snails to two other tanks, and left the goldfish alone in the final two tanks. she observed the rate of algae growth in each tank. in this experiment, which were part of a control group? the tanks with goldfish and ten snails the tanks with only goldfish

Explanation:

The control group in an experiment is the group that does not receive the treatment being tested. Here, the treatment is the addition of snails to control algae growth. The tanks with only goldfish have no snails added, so they serve as the baseline for comparison.

Answer:

the tanks with only goldfish